JP2007334027A - Image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image reader capable of emitting an appropriate quantity of excitation light and an appropriate quantity of erasing light to a record carrier without increasing costs and processing time. <P>SOLUTION: The image reader includes: an image reading section that reads radiographic image by emitting excitation light to a record carrier on which a radiographic image is accumulated and recorded by the emission of radiation holding an image, and then reading light emitted from the record carrier; an image erasing section that emits erasing light to the record carrier, thereby erasing radiographic image remaining on the record carrier after the radiographic image is read by the image reading section; an information capturing section that captures time information representing radiation time at which the radiographic image is accumulated and recorded on the record carrier subjected to the emission of the radiation; and a light quantity control section provided for the image reading section and/or image erasing section and used to adjust the intensity of the excitation light of the image reading section and/or the quantity of erasing light of the image erasing section based on the lapse of time obtained from the emission time represented by the time information acquired by the information acquiring section. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an image reading apparatus that reads a radiographic image accumulated and recorded on a record carrier and erases a radiographic image remaining on the record carrier after reading the radiographic image.

  Conventionally, a stimulable phosphor that accumulates a part of the radiation energy when irradiated with radiation and emits light according to the accumulated radiation energy when irradiated with visible light or the like is known. . In recent years, radiation that has passed through a subject is irradiated onto a stimulable phosphor to store and record a radiographic image, and the stimulable phosphor is irradiated with excitation light to emit stimulated emission light emitted from the stimulable phosphor. CR (Computed Radiography) that visualizes radiation images by reading them has been widely used in the medical field and the like.

  As a medical CR, an IP (imaging plate) with a stimulable phosphor affixed to the surface of a substrate is used together with a reading unit that irradiates the IP with a laser beam or the like to read the stimulated emission light. After the IP is stored in the built-in radiographic image reading device or the portable cassette in which radiation is applied to the IP stored in the device and in the state of being stored in the device, and the radiographic image is accumulated by imaging A cassette-type radiation image reading apparatus or the like is widely used. The cassette-type radiation image reading apparatus reads a radiation image by taking out the IP from the cassette.

  Further, in the radiographic image reading apparatus, not only the above-described reading unit, but also the IP after reading the radiographic image is irradiated with a laser beam or the like, and the radiation energy remaining in the IP is released to be stored and recorded. Generally, an erasing unit for erasing the radiation image is also housed together. By providing the erasing unit in the radiographic image reading apparatus, the IP after reading the radiographic image can be used repeatedly.

  As described above, the IP is irradiated with excitation light for generating stimulated emission light, erasing light for erasing the radiation image, and the like in addition to radiation. Usually, the higher the intensity of the excitation light irradiated to the IP, the higher the intensity of the stimulated emission light emitted from the IP, so that a clear radiation image can be obtained. As the amount of light increases, the amount of radiation energy emitted from the IP also increases, and the radiation image remaining in the IP can be erased reliably. For this reason, it is preferable to irradiate the IP with a large amount of excitation light or irradiation light in order to suppress the occurrence of a ghost due to an afterimage and acquire a clear radiation image. However, since IP deteriorates when irradiated with radiation or light, if a large amount of excitation light or erasing light is irradiated unnecessarily, the life of the IP is shortened and operation costs increase. There is a problem.

With respect to this problem, Patent Document 1 discloses a pre-reading operation for roughly reading a radiographic image by irradiating the IP with low-intensity excitation light before the actual reading operation for actually reading the radiographic image. A technique for determining various reading conditions during the main reading operation based on the wavelength of the stimulated emission light obtained during operation is described. According to the technique described in Patent Document 1, the intensity of excitation light necessary for acquiring a clear radiation image, the amount of erasing light necessary for reliably erasing the radiation image, and the like are estimated in advance. Therefore, it is possible to obtain a high-quality radiographic image and to prevent a problem that a large amount of light is unnecessarily irradiated and damages the IP.
Japanese Patent Laid-Open No. 4-156534

  However, in the technique described in Patent Document 1, a reading unit for pre-reading operation and a reading unit for main reading operation are provided in one device, which increases the manufacturing cost of the device. . Even if the reading unit for the pre-reading operation and the reading unit for the main reading operation can be shared, it is necessary to execute the pre-reading operation before the main reading operation. The processing time until an image is obtained is greatly increased. In recent years, it has been required to immediately confirm a radiographic image on the spot after imaging, to quickly detect imaging errors and perform re-imaging, and in the technique of Patent Document 1 that requires pre-reading operation, There is a problem of lack of immediacy.

  In view of the above circumstances, an object of the present invention is to provide an image reading apparatus that can irradiate a record carrier with an appropriate amount of excitation light or erasing light without increasing costs and processing time.

The image reading apparatus of the present invention that achieves the above object reads the light emitted from the record carrier by irradiating the record carrier on which the radiation image is accumulated and recorded with irradiation of the radiation carrying the image and irradiating excitation light. An image reading unit that reads a radiation image;
An image erasing unit that irradiates the record carrier with erasing light and erases the radiographic image remaining on the record carrier after the radiation image is read by the image reading unit;
An information acquisition unit for acquiring time information indicating an irradiation time when the record carrier is irradiated with radiation and accumulates and records a radiation image;
Based on the elapsed time from the irradiation time represented by the time information acquired by the information acquisition unit in the image reading unit and / or the image erasing unit, the intensity of excitation light in the image reading unit and / or the image erasing unit And a light amount control unit for adjusting the light amount of the erasing light.

  Conventionally, a fading phenomenon is known in which a radiographic image accumulated and recorded on a record carrier upon irradiation with radiation regresses with time. Using this fading phenomenon, the intensity of excitation light for reading the radiographic image decreases as the time elapsed since the radiographic image was accumulated and recorded (that is, the regression of the radiographic image has not progressed) , Increase the amount of erasing light for erasing the radiation image, and conversely, the longer the elapsed time (ie, the more the regression of the radiation image stored and recorded on the record carrier), the higher the intensity of the excitation light By reducing the amount of erasing light, the record carrier can be irradiated with moderately strong excitation light and moderate amount of erasing light, reducing damage to the record carrier and suppressing ghosting. It is possible to achieve both high quality and clear radiation image acquisition.

Further, in the image reading apparatus of the present invention, the information acquisition unit acquires time information and dose information representing the dose of radiation received by the record carrier,
The light amount control unit adjusts the intensity of the excitation light in the image reading unit and / or the light amount of the erasing light in the image erasing unit based on the elapsed time and the dose information acquired by the information acquisition unit. Preferably there is.

  Since the radiation energy accumulated on the record carrier changes depending on the radiation dose received by the record carrier, the intensity of the excitation light and the amount of erasing light applied to the IP are adjusted based on the elapsed time and the radiation dose. By doing so, the damage to the record carrier can be more reliably reduced.

The image reading apparatus of the present invention also includes a cumulative dose from the past of the radiation irradiated on the record carrier, an accumulated light quantity of the excitation light irradiated on the record carrier from the past, and an irradiation of the record carrier. A cumulative amount calculating unit for obtaining at least one cumulative amount of accumulated erasing light from the past,
It is preferable to include a warning unit that issues a warning when the cumulative amount obtained by the cumulative amount calculation unit reaches a predetermined limit value.

  The record carrier deteriorates every time it is irradiated with radiation or light, and when the deterioration reaches the limit, it becomes impossible to store and record a radiation image. When the cumulative amount of radiation or light irradiated on the record carrier reaches the limit value, a warning is issued, which makes it impossible to take a picture without realizing that the record carrier has reached the end of its life. It can be avoided.

Further, in the image reading apparatus of the present invention, the record carrier is accompanied by an information carrier for integrally storing and reading information including time information, which is fixed to the record carrier.
It is preferable that the information acquisition unit acquires time information stored in the information carrier from the information carrier.

  By fixing the information carrier on which the time information is stored to the record carrier, it is possible to reliably obtain the irradiation time when the radiographic image is accumulated and recorded on each record carrier even when multiple record carriers are mixed. can do.

  In the image reading apparatus of the present invention, the information carrier includes a light quantity recording unit for recording the light quantity of excitation light irradiated on the record carrier and / or the light quantity of erasing light irradiated on the record carrier. It is suitable.

  According to the preferred image reading apparatus of the present invention, the amount of light irradiated on the record carrier can be stored in association with the record carrier.

  According to the present invention, it is possible to irradiate the record carrier with an appropriate amount of excitation light or erasing light without increasing costs or processing time.

  Embodiments of the present invention will be described below with reference to the drawings.

  The present embodiment is applied to a cassette type radiography system in which an IP for accumulating and recording radiographic images is accommodated in a portable cassette, and the IP and an image reading device for reading radiographic images are separated. First, the configuration of the IP and cassette will be described.

  FIG. 1 is a schematic configuration diagram of an IP and a cassette, and FIG. 2 is a cross-sectional view when the cassette in which the IP is accommodated is cut along a plane passing through a straight line AA ′ in FIG.

  As shown in FIG. 1, the IP 10 is formed by depositing a stimulable phosphor 10A on a substrate (not shown), and is housed in a cassette 20 made of a material that transmits radiation. . In addition, the IP 10 is provided with a gripping frame 10B for a user to grip by hand when replacing the IP10 in the cassette 20 due to its life or damage. IP10 corresponds to an example of a record carrier according to the present invention.

  Leaf springs 10 a and 10 b are provided on the holding frame 10 </ b> B of the IP 10, and when the IP 10 is accommodated in the cassette 20, the leaf springs 10 a and 10 b are engaged with locking holes 21 a and 21 b provided in the cassette 20. By being stopped, the IP 10 is held in the cassette 20. Also, on the side of the cassette 20 opposite to the side on which the IP 10 is inserted, extrusion holes 22a and 22b for pushing the IP 10 out of the cassette 20 by inserting pins are provided. On the same side as the extrusion holes 22a and 22b, a reflection marker 23 on which the size of the cassette 20 is described is added. When the IP 10 is taken out from the cassette 20, a pin is inserted into the locking holes 21 a and 21 b to unlock the IP 10, and further, a pin is inserted into the extrusion holes 22 a and 22 b to put the IP 10 outside the cassette 20. Discharge.

  Further, as shown in FIG. 2, an RFID (Radio frequency) for reading and writing information by radio is provided on the back surface 20B of the cassette 20 opposite to the imaging surface 20A facing the IP10 storage phosphor 10A. identification) tag 24 is attached. The RFID tag 24 corresponds to an example of an information carrier referred to in the present invention.

  Next, a cassette type radiography system that accumulates and records radiation images in the IP 10 accommodated in the cassette 20 shown in FIGS. 1 and 2 and reads the radiation images will be described.

  FIG. 3 is a schematic configuration diagram of a cassette type radiation imaging system to which an embodiment of the image reading apparatus of the present invention is applied.

  The radiation imaging system 1 shown in FIG. 3 is an embodiment of a cassette 100 for fixing the cassette 20 shown in FIG. 1, a radiation irradiation apparatus 200 for irradiating radiation, and an image reading apparatus of the present invention. An image reading device 400 that reads the radiographic image and a control device 300 that controls the entire radiation imaging system 1 are provided, and the control device 300 is connected to the server device 500 via a LAN (Local Area Network).

  The cassette base 100 receives information to be recorded on the RFID tag 24 from the control unit 300 and the access unit 110 that writes information to the RFID tag 24 attached to the cassette 20 and reads information stored in the RFID tag 24. Or a communication unit 120 that transmits information read by the access unit 110 to the control device 300.

  The radiation irradiation device 200 includes a tube 210 that emits radiation, and a control unit 220 that adjusts the dose of radiation emitted from the tube 210 and transmits the dose of radiation emitted from the tube 210 to the control device 300. Is provided.

  In addition, the control device 300 has a display monitor 320 on which a radiographic image read by the image reading device 400, a radiation dose transmitted from the radiation irradiation device 200, various alarms, and the like are displayed, and a user instructs Is provided, and is connected to various elements shown in FIG. The display monitor 320 corresponds to an example of a warning unit according to the present invention.

  The image reading device 400 reads the radiation image stored and recorded in the IP 10 in the cassette 20 and sends the radiation image to the control device 300. The image reading device 400 will be described in detail later.

  The server device 500 is connected to various computers installed in the hospital and various systems in addition to the radiation imaging system 1 shown in FIG. 3, and the patient's medical record, radiation images, various information, and the like are collectively managed. ing. When the dose of the radiation irradiated by the radiation irradiation device 200 or the radiation image read by the image reading device 400 is transmitted from the control device 300 of the radiation imaging system 1, the server device 500 is sent from the control device 300. Various types of information are stored together with identification information for identifying the IP 10 in the cassette 20.

  At the time of photographing, first, the user inserts the IP 10 into the cassette 20 and fixes the cassette 20 to the cassette base 100. Subsequently, the subject 2 is moved in front of the cassette table 100, the position and height of the radiation irradiation apparatus 200 are adjusted, and the irradiation position of the radiation emitted from the radiation irradiation apparatus 200 is adjusted to the imaging region of the subject 2.

  When the user presses the emission button for instructing the emission of radiation in the operator 310 of the control device 300, the emission instruction is transmitted from the control device 300 to the radiation irradiation device 200, and the radiation is emitted from the radiation irradiation device 200. The radiation emitted from the radiation irradiating apparatus 200 passes through the subject 2 and further passes through the cassette 20 before being irradiated onto the IP 10. As a result, the radiation image is accumulated and recorded in the IP 10.

  When shooting is completed, the cassette 20 is removed from the cassette base 100 and mounted on the image reading apparatus 400.

  FIG. 4 is an external perspective view of an image reading apparatus 400 which is an embodiment of the image reading apparatus of the present invention, and FIG. 5 is an internal configuration diagram of the image reading apparatus 400.

  As shown in FIG. 4, at both ends of the image reading apparatus 400, there are a carry-in port 401A on which a cassette 20 from which a radiographic image will be read is placed, and an outlet 401B from which the cassette 20 from which the radiographic image has been read is discharged. In the center of the image reading apparatus 400, a display panel 401C for displaying the operating state of the image reading apparatus 400 and the like is provided. The display panel 401C also corresponds to an example of a warning unit according to the present invention.

  As shown in FIG. 5, the carry-in port 401 </ b> A is inclined downward as it is farther from the center, and a lid member 410 </ b> A for taking the cassette 20 into the image reading apparatus 400 is disposed at the lowest part of the inclination. Yes. The carry-in port 401A is provided with a sensor (not shown) for reading the reflective marker 23 (see FIG. 1) added to the bottom of the cassette 20.

  Inside the image reading device 400, roughly divided, the conveyance unit 420 that conveys the cassette 20 between the carry-in port 401A and the discharge port 401B, the reading unit 430 that reads the radiographic image accumulated and recorded in the IP10, and remains on the IP10. An erasing unit 440 for erasing a radiation image to be performed, an information acquisition unit 450 for reading information stored in the RFID tag 24 attached to the cassette 20, an information writing unit 460 for writing information to the RFID tag 24, and the entire image reading device 400 And a control unit 470 that transmits a radiation image toward the control device 300 shown in FIG. 3. The reading unit 430 corresponds to an example of the image reading unit according to the present invention, and the erasing unit 440 corresponds to an example of the image erasing unit according to the present invention. The information acquisition unit 450 is an example of the information acquisition unit according to the present invention, the information writing unit 460 is an example of the light amount recording unit according to the present invention, and the control unit 470 is the light amount control unit according to the present invention. It corresponds to an example of each cumulative amount calculation unit.

  When the reflective marker 23 added to the cassette 20 is read by the sensor described above, the information acquisition unit 450 reads information stored in the RFID tag 24 of the cassette 20. The read information is transmitted to the control unit 470. Based on this information, the control unit 470 determines whether or not the cassette 20 is of a type that is permitted to be attached to the image reading apparatus 400. If the cassette 20 is of a type that is not permitted to be attached to the image reading apparatus 400, an error message is displayed on the display panel 401C shown in FIG. 4 and entry into the image reading apparatus 400 is prohibited.

  If the cassette 20 is of a type that is permitted to be attached to the image reading device 400, the radiation stored and recorded in the IP 10 based on the information read from the RFID tag 24 in the control unit 470. The intensity of the excitation light L for reading the image, the light amount of the erasing light Q for erasing the radiation image, and the like are determined. Information obtained from the RFID tag 24 will be described later. Further, in accordance with an instruction from the control unit 470, a motor attached to the lid member 410A of the carry-in port 401A is driven to open the lid member 410A, and the cassette 20 placed on the carry-in port 401A is transferred to the carrying unit 420 by the carrying roll 4211. Be transported.

  The transport unit 420 has two upper and lower portions connecting the loading position S1 below the carry-in port 401A, the reading position S2 below the reading unit 430, the erasing position S3 below the erasing unit 440, and the discharging position S4 below the discharge port 401B. The guide rails 422 and 423 are provided, and a transport member 424 that transports the cassette 20 between the loading position S1 and the discharge position S4 by moving along the guide rails 422 and 423 is provided.

  The cassette 20 transported by the transport roll 4211 is first held by the transport member 424 at the loading position S1 and transported to the reading position S2 along the guide rails 422 and 423. At the reading position S2, discharge portions 425 and 426 each including two pins and a solenoid for inserting and removing these pins are arranged side by side. When the cassette 20 is conveyed to the reading position S2, pins provided in the upper discharge portion 425 are inserted into the locking holes 21a and 21b of the cassette 20 shown in FIG. The IP 10 is unlocked, the pins provided in the lower discharge portion 425 are inserted into the extrusion holes 22 a and 22 b of the cassette 20, and the IP 10 is pushed out of the cassette 20. The IP 10 discharged from the cassette 20 is transferred to the reading unit 430 by the transfer roll 4212, and the empty cassette 20 from which the IP 10 has been discharged is transferred along the guide rails 422 and 423 to the erasing position S3.

  The reading unit 430 is provided with a conveyance path R extending vertically upward, and the shutters 431A and 431B provided at two places where the IP10 enters and exits, and the excitation light L in the main scanning direction (the depth direction of the paper surface). An excitation light irradiating unit 433 for irradiating the laser beam, an image reading unit 435 for condensing the stimulated emission light by a condensing guide 434 extending in the main scanning direction, and reading a radiographic image accumulated and recorded in the IP 10; Two extended upper and lower guide rails 436 and 437 and a pair of upper and lower nip rolls 438 and 439 that move along the guide rails 436 and 437 in the horizontal direction are provided.

  The IP 10 discharged from the cassette 20 is transported upward along the transport path R toward the guide rails 436 and 437 by the transport rolls 4212 and 4321. When the tip of the IP 10 reaches the position of the excitation light irradiation unit 433, the shutters 431A and 431B are closed and the reading unit 430 is shielded from light. The IP 10 is further transported upward by the transport rollers 4322 and 4323, and subsequently, the excitation light L having the intensity determined by the control unit 470 is irradiated from the excitation light irradiation unit 433 to the IP 10 being transported, and the image reading unit The stimulated emission light emitted from IP10 is read by 435. The radiation image read by the image reading unit 435 is transmitted to the control unit 470 and sent to the control device 300 shown in FIG.

  The IP 10 from which the radiation image has been read is transported to the nip rolls 438 and 439 by the transport rolls 4322 and 4323, and is sandwiched between the nip rolls 438 and 439. The nip rolls 438 and 439 move in the horizontal direction along the guide rails 436 and 437 while holding the IP 10 and, when reaching the ends of the guide rails 436 and 437, convey the IP 10 downward. The IP 10 is transported to the erasing unit 440 by being further moved downward by the transport rolls 4324 and 4213.

  The erasing unit 440 is provided with a plurality of fluorescent lamps 441 extending both in the main scanning direction (depth direction in the figure) and in the sub-scanning direction (vertical direction). When the erasing light Q having a light amount determined by the control unit 470 is emitted from the plurality of fluorescent lamps 441, the erasing light Q is applied to the IP 10 being conveyed. As a result, the radiation energy accumulated in the IP 10 is released and the radiation image is erased.

  The IP10 from which the radiographic image has been erased is further conveyed downward by the conveyance roll 4214, and is accommodated in the empty cassette 20 that has been conveyed to the erasing position S3. An information writing unit 460 is disposed at the erasing position S3, and various information is written to the RFID tag 24 attached to the cassette 20. Information written to the RFID tag 24 will also be described later.

  The cassette 20 containing the IP 10 after the radiation image is read and the radiation energy is erased is conveyed along the guide rails 422 and 423 to the discharge position S4.

  The discharge port 401B is also provided with a lid member 410B as in the carry-in port 401A. When the cassette 20 is conveyed to the discharge position S4, the cover member 410B of the discharge port 401B is opened. The cassette 20 transported to the discharge position S4 is transported toward the discharge port 401B by the transport roll 4215 and discharged from the discharge port 401B.

  The image reading apparatus 400 is basically configured as described above.

  Here, in the image reading apparatus 400 of the present embodiment, the intensity of the excitation light L and the amount of the erasing light Q are adjusted by the control unit 470, and the lifetime of the IP 10 is further based on the amount of light and radiation irradiated by the IP 10. Determined. Hereinafter, a method for adjusting the intensity of the excitation light L and the erasing light Q and a method for determining the lifetime of the IP 10 will be described in detail.

  FIG. 6 is a flowchart showing a flow of a series of processes at the time of radiographic image capturing.

  As described above, the cassette 20 is attached with the RFID tag 24 for performing information access using radio. In photographing, various types of information stored in the RFID tag 24 are acquired in the access unit 110 of the cassette base 100 (step S11 in FIG. 6).

  Table 1 is a table showing information stored in the RFID tag 24.

  The RFID tag 24 includes IP information including a cassette ID indicating the manufacturer and type of the IP 10 and the cassette 20, a life calculation value (to be described later) for determining the life of the IP 10, an imaging region, and imaging. Reading composed of imaging information composed of date and time and radiation dose emitted at the time of photographing, intensity of excitation light L at the time of reading of the radiation image, and amount of erasing light Q at the time of erasing of the radiation image Information, a photographing prohibition flag (1: photographing prohibition, 0: photographing permission) indicating prohibition of photographing, and a photographing warning flag (1: notification required, 0: notification not required) indicating a warning of photographing attention are stored. Yes. The cassette ID of the IP information is stored in advance at the time of shipment or the like, and the shooting information is updated by the access unit 110 of the cassette base 100, and other items (IP information lifetime calculation value, read information, shooting prohibition flag, And the shooting warning flag) are updated by the information writing unit 460 of the image reading apparatus 400.

  Various information acquired by the access unit 110 of the cassette base 100 is transmitted to the control device 300 via the communication unit 120.

  In the control device 300, based on the cassette ID of the IP information shown in Table 1, whether the cassette 20 and the IP 10 mounted on the cassette base 100 are of a type that is permitted to be mounted on the image reading device 400. It is determined whether or not (step S12 in FIG. 6).

  When the cassette 20 and the IP 10 are not of a type that is permitted to be attached to the image reading device 400 (step S12 in FIG. 6: No), the control device 300 displays “This cassette is A message saying “cannot be used” is displayed (step S13 in FIG. 6), and radiation emission in the radiation irradiation apparatus 200 is prohibited. If the cassette 20 of the wrong type is forcibly attached to the image reading apparatus 400, the image reading apparatus 400 may break down. In addition, if an image is taken without noticing that the type of cassette 20 is incorrect, it is necessary to perform imaging again using the correct cassette 20, and the subject must be exposed to radiation that is harmful to the human body many times. Don't be. In the present embodiment, whether or not the cassette 20 can be attached to the image reading apparatus 400 is notified before photographing, so that it is possible to avoid failure of the apparatus and unnecessary re-imaging.

  When the cassette 20 and the IP 10 are of a type that is permitted to be attached to the image reading device 400 (step S12 in FIG. 6: Yes), the photographing prohibition flag stored in the RFID tag 24 is set. It is determined whether or not the value is “1: photographing prohibited” (step S16 in FIG. 6).

  When the value of the photographing prohibition flag is “1: photographing prohibition” (step S14 in FIG. 6: Yes), the control device 300 displays a message “IP is at the end of life” on the display monitor 320. (Step S15 in FIG. 6), radiation emission in the radiation irradiation apparatus 200 is prohibited.

  When the value of the photographing prohibition flag is “0: photographing permitted” (step S14: No in FIG. 6), the value of the photographing warning flag stored in the RFID tag 24 is “1: notification required”. It is determined whether or not there is (step S17 in FIG. 6).

  When the value of the shooting warning flag is “1: notification required” (step S17 in FIG. 6: Yes), a message stating “IP life is approaching” is displayed on the display monitor 320 of the control device 300. (Step S17 in FIG. 6) and a message “Do you want to continue shooting?” Is also displayed.

  When the user selects “cancel imaging” using the operator 310 (step S18 in FIG. 6: No), the radiation irradiation apparatus 200 is prohibited from emitting radiation and imaging is stopped.

  Since IP deteriorates when irradiated with radiation or laser light, if it continues to be used, it becomes impossible to store and record a radiation image. By notifying the IP life before shooting, shooting errors can be prevented.

  When “continuation of photographing” is selected by the user (step S18 in FIG. 6: Yes), or the IP 10 and the cassette 20 are of a type suitable for the image reading apparatus 400 (step S12 in FIG. 6: Yes). ), When the value of the photographing prohibition flag is “0: photographing permitted” (step S14 in FIG. 6: No), and the value of the photographing warning flag is “0: notification is not necessary” (step S16 in FIG. 6: No), the actual shooting is started. First, the user inputs an imaging region using the operator 310 (step S19 in FIG. 6). The input imaging part is transmitted from the control device 300 to the communication unit 120 of the cassette 100 and stored in the RFID tag 24 by the access unit 110 (step S20 in FIG. 6).

  Subsequently, when the user instructs the emission of radiation using the operator 310 of the control device 300, the radiation is emitted from the tube 210 of the radiation irradiation device 200. Radiation emitted from the radiation irradiation apparatus 200 passes through the subject 2 and is irradiated to the IP 10 accommodated in the cassette 20. As a result, the radiation image of the subject 2 is accumulated and recorded on the IP 10 (step S21 in FIG. 6).

  When imaging is completed, the control unit 220 of the radiation irradiation apparatus 200 transmits the radiation dose emitted from the tube 210 to the control apparatus 300, and the control apparatus 300 communicates the radiation dose and the imaging date / time with the cassette 100. Tell part 120. The access unit 110 of the cassette table 100 stores the radiation dose and the imaging date / time transmitted from the control device 300 in the RFID tag 24 (step S22 in FIG. 6).

  Further, when communication is established between the control device 300 and the server device 500 (step S23 in FIG. 6: Yes), the cassette ID, the imaging date and time, and the radiation information are transferred from the control device 300 to the server device 500. The dose is transmitted (step S24 in FIG. 6), and the information is also stored in the server device 500. By storing these pieces of information not only in the RFID tag 24 but also in the server apparatus 500, the intensity of the excitation light L and the erasing light Q can be adjusted even when the RFID tag 24 is damaged. In addition, it is possible to determine the life of the IP10.

  The radiographic image is captured as described above.

  FIG. 7 is a flowchart showing a flow of a series of processes at the time of image reading.

  When the photographing is completed, the cassette 20 is placed on the carry-in port 401A of the image reading apparatus 400 shown in FIG. 5 (step S31 in FIG. 7). When the cassette 20 is placed and the reflective marker 23 (see FIG. 1) attached to the cassette 20 is read by a sensor (not shown) provided at the bottom of the carry-in port 401A, the information acquisition unit 450 causes the RFID tag to be read. The information (see Table 1) stored in 24 is read (step S32 in FIG. 7). Information read by the information acquisition unit 450 is transmitted to the control unit 470.

  In the control unit 470, based on the cassette ID in the read information, whether or not the cassette 20 placed on the carry-in port 401A is of a type permitted to be mounted in the image reading apparatus 400. Is determined (step S33 in FIG. 7).

  When the cassette 20 is not of a type that is permitted to be attached to the image reading apparatus 400 (step S33: No in FIG. 7), the control unit 470 displays “This cassette” on the display panel 401C shown in FIG. Is displayed ”(step S34 in FIG. 7). By determining whether or not the cassette 20 is the correct cassette 20 before the cassette 20 is conveyed into the image reading apparatus 400, the wrong cassette 20 is forcibly mounted in the image reading apparatus 400 and the image is read. It is possible to reliably avoid the problem that the reading device 400 and the IP 10 in the cassette 20 are damaged.

  When the cassette 20 is of a type that is permitted to be attached to the image reading apparatus 400 (step S33 in FIG. 7: Yes), the cassette 20 is conveyed into the image reading apparatus 400 by the conveying roll 4211. .

  Further, when communication between the control device 300 and the server device 500 is established and communication between the control device 300 and the image reading device 400 is established (step S35 in FIG. 7: Yes), image reading is performed. The control unit 470 of the device 400 acquires information (cassette ID, imaging date and time, and radiation dose) stored in the server device 500 in step S24 of FIG. 6 via the control device 300 (step S36 of FIG. 7). ).

  Subsequently, the control unit 470 compares the information acquired from the server device 500 with the information stored in the RFID tag 24 and determines which is the latest information that has not been destroyed and has the latest shooting date and time. (Step S37 in FIG. 7). When the information acquired from the server device 500 is not destroyed and is the latest information (step S37 in FIG. 7: server device side information), it is determined to adopt the information acquired from the server device 500. (Step S38 in FIG. 7). In addition, when the information stored in the RFID tag 24 is not destroyed and is the latest information (step S37 in FIG. 7: RFID information), the communication between the image reading device 400 and the server device 500 is performed. If it has not been established (step S25 in FIG. 7: No), it is determined to adopt the information stored in the RFID tag 24 (step S39 in FIG. 7).

  Further, the control unit 470 calculates the elapsed time from the latest shooting date / time in the information determined to be adopted to the current time (step S40 in FIG. 7).

  Here, in the present embodiment, a correspondence relationship between the elapsed time since shooting, the intensity of the excitation light L, and the light quantity of the erasing light Q is prepared in advance.

  FIG. 8 is a graph showing changes in the amount of radiation energy accumulated in the IP, the intensity of the excitation light L, and the elapsed time of the amount of the erasing light Q.

  In the graph of FIG. 8A, the horizontal axis indicates the elapsed time after imaging, and the vertical axis indicates the amount of radiation energy remaining in the IP10. The radiation energy accumulated in the IP 10 decreases with time (fading phenomenon).

  In the graph of FIG. 8B, the horizontal axis indicates the elapsed time after imaging, and the vertical axis indicates the intensity of the excitation light L necessary for reading the radiation image accumulated and recorded in the IP10. As shown in FIG. 8A, the radiation energy accumulated in the IP 10 decreases with time, so the intensity of the excitation light L required to excite the radiation energy increases with time. It will become.

  In the graph of FIG. 8C, the horizontal axis indicates the elapsed time after imaging, and the vertical axis indicates the amount of the erasing light Q necessary for releasing the radiation energy remaining in the IP10. As the amount of radiation energy remaining in the IP 10 decreases with the passage of time, the amount of the erasing light Q required to release the radiation energy and erase the radiation image is increased with the passage of time. It will decrease.

  Further, when the initial radiation energy amount E0 accumulated in the IP 10 at the time of imaging changes, the graph of FIG. 8A shifts in the vertical axis by an amount corresponding to the change of the initial radiation energy amount E0, and FIG. ) And the graph of FIG. 8C are also shifted in the vertical axis by an amount corresponding to the change in the initial radiation energy amount E0.

  In this embodiment, according to the various graphs shown in FIG. 8, for each initial radiation energy amount E0 accumulated in the IP 10 at the time of imaging, the elapsed time after imaging, the intensity of the excitation light L, and the light intensity of the erasing light Q Corresponding in advance. The control unit 470 uses the excitation light L associated with the radiation dose (step S38 or step S39 in FIG. 7) and the calculated elapsed time (step S40 in FIG. 7) in the information determined to be adopted. And the amount of erasing light Q are acquired (step S41 in FIG. 7). The intensity of the acquired excitation light L is transmitted to the reading unit 430, and the amount of the erasing light Q is transmitted to the erasing unit 440.

  When the cassette 20 is mounted in the image reading apparatus 400, the IP 10 accommodated in the cassette 20 is taken out. The IP 10 is conveyed to the reading unit 430 and irradiated with the excitation light L having the intensity transmitted from the control unit 470 to read the stimulated emission light, thereby reading the accumulated and recorded radiation image (step of FIG. 7). S42). The read radiographic image is sent to the control device 300 by the control unit 470 and displayed on the display monitor 320 of the control device 300. Further, when the server device 500 is connected to the control device 300, a radiographic image is sent from the control device 300 to the server device 500, and the radiographic image is stored in the server device 500.

  The IP 10 from which the radiographic image has been read is conveyed to the erasing unit 440 and irradiated with the amount of erasing light Q transmitted from the control unit 470, whereby the accumulated radiation energy is released and the radiographic image is displayed. It is erased (step S43 in FIG. 7).

  According to the image reading apparatus 400 of the present embodiment, since the excitation light L and the erasing light Q having the intensity corresponding to the radiation energy remaining on the IP 10 are irradiated, a large amount of light is unnecessarily irradiated to the IP 10. Problems can be prevented and the life of the IP 10 can be improved.

  When the irradiation with the excitation light L and the erasing light Q is completed, the control unit 470 transmits the intensity of the excitation light L and the amount of the erasing light Q to the information writing unit 460. The information writing unit 460 stores the intensity of the excitation light L and the amount of the erasing light Q transmitted from the control unit 470 in the RFID tag 24 attached to the cassette 20.

  In addition, the control unit 470 calculates the lifetime of the IP 10 based on various information stored in the RFID tag 24. The lifetime of IP10 is calculated by the following equation (1).

Hc = α × El + β × Eq + Hc_p (1)
However, Hc is a calculated lifetime value, α is an intensity factor of excitation light, El is an intensity of excitation light L, β is a light amount coefficient of erasing light, Eq is an erasing light amount, and Hc_p is a calculated lifetime value stored in the RFID tag 24. Indicates. The calculated life value Hc corresponds to an example of the cumulative amount referred to in the present invention.

  When the calculated lifetime calculation value Hc is larger than the predetermined photographing prohibition limit value H_Iim (step S45 in FIG. 7: Yes), the control unit 470 instructs the information writing unit 460 to set the photographing prohibition flag. Then, the information writing unit 460 updates the photographing prohibition flag stored in the RFID tag 24 attached to the cassette 20 to “1: photographing prohibition” (step S46 in FIG. 7).

  Further, the calculated life calculation value Hc is equal to or less than the photographing prohibition limit value H_Iim (step S45: No in FIG. 7), and a predetermined life warning limit value H_war (however, the photographing prohibition limit value H_Iim> life warning limit) When the value is larger than (value H_war) (step S45 in FIG. 7: Yes), the control unit 470 instructs the information writing unit 460 to set the shooting warning flag, and the information writing unit 460 is stored in the RFID tag 24. The shooting warning flag is updated to “1: notification required” (step S48 in FIG. 7).

  Further, the control unit 470 transmits the calculated lifetime value Hc to the information writing unit 460, and the information writing unit 460 transmits the calculated lifetime value stored in the RFID tag 24 to the new lifetime that is transmitted from the control unit 470. The calculated value Hc is updated (step S49 in FIG. 7).

  When the writing of information to the RFID tag 24 is completed, the cassette 20 in which the IP 10 is accommodated is discharged out of the image reading apparatus 400.

  As described above, according to the image reading apparatus 400 of the present embodiment, the IP 10 can be irradiated with the excitation light L and the erasing light Q having appropriate intensities, thereby reducing the damage to the IP and suppressing the occurrence of ghosts. It is possible to achieve both high quality and clear radiation image acquisition.

  Here, in the above description, an example in which the image reading apparatus performs the process of calculating the life calculation value and updating the shooting prohibition flag and the shooting warning flag has been described. However, these processes are performed not by the image reading apparatus but by the control apparatus or the like. You may do it.

  In the above description, the example in which the lifetime is calculated based on the cumulative light amount of the excitation light and the cumulative light amount of the erasing light has been described. However, the cumulative amount calculation unit according to the present invention calculates the cumulative dose of radiation. There may be.

  In the above description, an example in which the shooting date and time is recorded on the RFID tag attached to the cassette has been described. However, the record carrier according to the present invention may be other than the RFID tag, and directly on the IP instead of the cassette. It may be attached.

  In the above description, an example in which the RFID tag storing the shooting date and time is attached to the cassette has been described. However, the image reading apparatus of the present invention prints a barcode or the like indicating the shooting date and time on the cassette, It may be read by a code reader or the like.

  Further, in the above description, an example in which information such as the shooting date and time is stored in the RFID tag and the server device has been described. However, the image reading device of the present invention stores such information in the image reading device. Also good.

It is a schematic block diagram of IP and a cassette. It is sectional drawing when cut | disconnecting the cassette in which IP was accommodated in the surface which passes along the straight line AA 'of FIG. It is a schematic block diagram of a cassette type radiation imaging system. 1 is an external perspective view of an image reading device. It is an internal block diagram of an image reading apparatus. It is a flowchart which shows the flow of a series of processes at the time of imaging | photography. It is a flowchart which shows the flow of a series of processes at the time of image reading. It is a graph which shows the change according to the elapsed time of the radiation energy amount accumulate | stored in IP, the intensity | strength of the excitation light L, and the light quantity of the erasing light Q.

Explanation of symbols

1 Radiography system 2 Subject 10 IP
10A Storage phosphor 10B Grip frame 10a, 10b Leaf spring 20 Cassette 21a, 21b Locking hole 22a, 22b Extrusion hole 23 Reflective marker 100 Cassette base 110 Access unit 120 Communication unit 200 Radiation irradiation device 210 Tube 220 Control unit 300 Control Device 310 Operator 320 Display monitor 400 Image reader 401A Carry-in port 401B Discharge port 401C Display panel 410A, 410B Lid member 420 Conveying unit 422, 423 Guide rail 424 Conveying member 430 Reading unit 431A, 431B Shutter 433 Excitation light irradiation unit 434 Collection Light guide 435 Image reading unit 436, 437 Guide rail 438, 439 Nip roll 440 Erasing unit 441 Fluorescent lamp 450 Information acquisition unit 460 Information writing unit 470 Control unit

Claims (5)

An image reading unit that reads the radiation image by irradiating the record carrier on which the radiation image is accumulated and recorded by receiving the radiation carrying the image, irradiating excitation light, and reading the light emitted from the record carrier;
An image erasing unit that irradiates the record carrier with erasing light and erases a radiographic image remaining on the record carrier after a radiographic image is read by the image reading unit;
An information acquisition unit for acquiring time information indicating an irradiation time when the record carrier is irradiated with radiation and accumulates and records the radiation image;
Based on the elapsed time from the irradiation time represented by the time information acquired by the information acquisition unit in the image reading unit and / or the image erasing unit, and / or the intensity of excitation light in the image reading unit, and / or An image reading apparatus comprising: a light amount control unit that adjusts a light amount of erasing light in the image erasing unit. The information acquisition unit acquires the time information, and acquires dose information representing the dose of radiation received by the record carrier,
The light amount control unit is based on the elapsed time, and based on the dose information acquired by the information acquisition unit, the intensity of excitation light in the image reading unit and / or the light amount of erasing light in the image erasing unit The image reading apparatus according to claim 1, wherein the image reading apparatus is adjusted. The cumulative dose from the past of the radiation irradiated by the record carrier, the cumulative amount of excitation light from the past irradiated by the record carrier, and the past of the erasing light irradiated by the record carrier An accumulated amount calculating unit for obtaining at least one accumulated amount of accumulated light amounts from:
The image reading apparatus according to claim 1, further comprising: a warning unit that issues a warning when the cumulative amount obtained by the cumulative amount calculation unit reaches a predetermined limit value. The record carrier is accompanied by an information carrier for integrally storing and reading information including the time information fixed to the record carrier,
The image reading apparatus according to claim 1, wherein the information acquisition unit acquires time information stored in the information carrier from the information carrier.   The light quantity recording unit for recording the light quantity of excitation light irradiated on the record carrier and / or the light quantity of erasing light irradiated on the record carrier on the information carrier. 5. The image reading apparatus according to 4.

Images